CALL THE Department of Social Services van: I showed “The Jazz Singer” to my children. The groundbreaking 1927 talkie has recently been released in a three-DVD 80th anniversary set, and it remains weirdly entertaining. My two daughters, old hands at old movies, were enthralled. About two-thirds of the way in, though, the film suddenly turns the corner into unforgivable pop travesty: Al Jolson sits at a backstage makeup table and applies burnt cork to his face. Pulls on a nappy wig. Becomes a cartoon black man, singing “Mother of Mine, I Still Have You.”

The kids were appalled. How could someone do that? Didn’t the filmmakers understand it was racist?

Welcome, my children, to your culture’s dirty secret.

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